A new Canadian study has found the women who live in wealthy neighborhoods within 220 yards of a highway have a 58% increased chance of preterm birth and an 81% chance of an increased risk of low birth weight. There were no adverse birth effects associated with poorer neighborhoods that are closer to highways. The lead author of the study suggests that because wealthier mothers are less at risk for other factors for a low birth weight — such as smoking, and poor access to prenatal care — they might have a higher risk of being affected by pollution. So being healthy during pregnancy means you are more likely to be affected by pollution? Or maybe some moms are just not taking care of themselves, regardless of their income? [NY Times]